The official explanation is that "Super Bowl L" just isn't as pleasing to the eye as its Arabic numeral equivalent, "Super Bowl 50."

"When we developed the Super Bowl XL logo, that was the first time we looked at the letter L," Jaime Weston, the league's vice president of brand and creative, is quoted as saying by ESPN. "Up until that point, we had only worked with X's, V's and I's. And, at that moment, that's when we started to wonder: What will happen when we get to 50?"

Super Bowl 50, set to be played at San Francisco's Levi's Stadium, will be the first championship to carry an Arabic numeral designation since Roman numerals were introduced in 1971 for Super Bowl V.

The NFL says it will revert to Roman numerals beginning with Super Bowl LI in 2017.

ESPN reports:

"As part of the final testing of the logos, including how the gold would play, the league looked at them on Wilson game footballs and even painted a logo on the playing surface at Candlestick Park last week.

"Following the conclusion of Super Bowl XLIX, which will be played at the University of Phoenix Stadium in Arizona on Feb. 1, 2015, the league will embark on a campaign to play up the 50th anniversary. The NFL will go back to using Roman numerals for Super Bowl LI in Houston in 2017.

"The league started using the term 'Super Bowl' for the third game in 1969. The league filed to trademark the term two months later."